Matthew Sparkes writes: "Tom Van Baak and his three young children performed an impressive experiment on the theory of relativity. The group took a van equipped with 3 atomic clocks up Mount Rainier, near Seattle, for a couple of days camping. Because of the altitude, and therefore speed difference, they could calculate that there would be a time dilation of +22 nanoseconds between the two vans clocks, and some left at their house. If everyone's dad was like this then the world would be filled with theoretical physicists."